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Your search keyword '"Nishimiya H"' showing total 4 results
Start Over Author "Nishimiya H" Journal physical review letters
4 results on '"Nishimiya H"'

1. Study of the KL→π0νν¯ Decay at the J-PARC KOTO Experiment

Author

Ahn, JK, Beckford, B, Campbell, M, Chen, SH, Comfort, J, Dona, K, Farrington, MS, Hanai, K, Hara, N, Haraguchi, H, Hsiung, YB, Hutcheson, M, Inagaki, T, Isoe, M, Kamiji, I, Kato, T, Kim, EJ, Kim, JL, Kim, HM, Komatsubara, TK, Kotera, K, Lee, SK, Lee, JW, Lim, GY, Lin, QS, Lin, C, Luo, Y, Mari, T, Masuda, T, Matsumura, T, Mcfarland, D, McNeal, N, Miyazaki, K, Murayama, R, Nakagiri, K, Nanjo, H, Nishimiya, H, Noichi, Y, Nomura, T, Nunes, T, Ohsugi, M, Okuno, H, Redeker, JC, Sanchez, J, Sasaki, M, Sasao, N, Sato, T, Sato, K, Sato, Y, Shimizu, N, Shimogawa, T, Shinkawa, T, Shinohara, S, Shiomi, K, Shiraishi, R, Su, S, Sugiyama, Y, Suzuki, S, Tajima, Y, Taylor, M, Tecchio, M, Togawa, M, Toyoda, T, Tung, Y-C, Vuong, QH, Wah, YW, Watanabe, H, Yamanaka, T, Yoshida, HY, and Zaidenberg, L

Subjects
Particle and High Energy Physics, Physical Sciences, KOTO Collaboration, hep-ex, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

The rare decay K_{L}→π^{0}νν[over ¯] was studied with the dataset taken at the J-PARC KOTO experiment in 2016, 2017, and 2018. With a single event sensitivity of (7.20±0.05_{stat}±0.66_{syst})×10^{-10}, three candidate events were observed in the signal region. After unveiling them, contaminations from K^{±} and scattered K_{L} decays were studied, and the total number of background events was estimated to be 1.22±0.26. We conclude that the number of observed events is statistically consistent with the background expectation. For this dataset, we set an upper limit of 4.9×10^{-9} on the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level.

Published
2021

2. Search for <math><mrow><msub><mrow><mi>K</mi></mrow><mrow><mi>L</mi></mrow></msub><mo>→</mo><msup><mrow><mi>π</mi></mrow><mrow><mn>0</mn></mrow></msup><mi>ν</mi><mover><mrow><mi>ν</mi></mrow><mrow><mo>¯</mo></mrow></mover></mrow></math> and <math><msub><mi>K</mi><mi>L</mi></msub><mo>→</mo><msup><mi>π</mi><mn>0</mn></msup><msup><mi>X</mi><mn>0</mn></msup></math> Decays at the J-PARC KOTO Experiment

Author

Ahn, J. K., Beckford, B., Beechert, J., Bryant, K., Campbell, M., Chen, S. H., Comfort, J., Dona, K., Hara, N., Haraguchi, H., Hsiung, Y. B., Hutcheson, M., Inagaki, T., Kamiji, I., Kawasaki, N., Kim, E. J., Kim, J. L., Kim, Y. J., Ko, J. W., Komatsubara, T. K., Kotera, K., Kurilin, A. S., Lee, J. W., Lim, G. Y., Lin, C., Lin, Q., Luo, Y., Ma, J., Maeda, Y., Mari, T., Masuda, T., Matsumura, T., Mcfarland, D., McNeal, N., Micallef, J., Miyazaki, K., Murayama, R., Naito, D., Nakagiri, K., Nanjo, H., Nishimiya, H., Nomura, T., Ohsugi, M., Okuno, H., Sasaki, M., Sasao, N., Sato, K., Sato, T., Sato, Y., Schamis, H., Seki, S., Shimizu, N., Shimogawa, T., Shinkawa, T., Shinohara, S., Shiomi, K., Su, S., Sugiyama, Y., Suzuki, S., Tajima, Y., Taylor, M., Tecchio, M., Togawa, M., Tung, Y. C., Wah, Y. W., Watanabe, H., Woo, J. K., Yamanaka, T., and Yoshida, H. Y.

Abstract

A search for the rare decay KL→π0νν¯ was performed. With the data collected in 2015, corresponding to 2.2×1019 protons on target, a single event sensitivity of (1.30±0.01stat±0.14syst)×10−9 was achieved and no candidate events were observed. We set an upper limit of 3.0×10−9 for the branching fraction of KL→π0νν¯ at the 90% confidence level (C.L.), which improved the previous limit by almost an order of magnitude. An upper limit for KL→π0X0 was also set as 2.4×10−9 at the 90% C.L., where X0 is an invisible boson with a mass of 135 MeV/c2.

Published
2019

3. Study of the K&#95;{L}→π^{0}νν[over ¯] Decay at the J-PARC KOTO Experiment.

Author

Ahn JK, Beckford B, Campbell M, Chen SH, Comfort J, Dona K, Farrington MS, Hanai K, Hara N, Haraguchi H, Hsiung YB, Hutcheson M, Inagaki T, Isoe M, Kamiji I, Kato T, Kim EJ, Kim JL, Kim HM, Komatsubara TK, Kotera K, Lee SK, Lee JW, Lim GY, Lin QS, Lin C, Luo Y, Mari T, Masuda T, Matsumura T, Mcfarland D, McNeal N, Miyazaki K, Murayama R, Nakagiri K, Nanjo H, Nishimiya H, Noichi Y, Nomura T, Nunes T, Ohsugi M, Okuno H, Redeker JC, Sanchez J, Sasaki M, Sasao N, Sato T, Sato K, Sato Y, Shimizu N, Shimogawa T, Shinkawa T, Shinohara S, Shiomi K, Shiraishi R, Su S, Sugiyama Y, Suzuki S, Tajima Y, Taylor M, Tecchio M, Togawa M, Toyoda T, Tung YC, Vuong QH, Wah YW, Watanabe H, Yamanaka T, Yoshida HY, and Zaidenberg L

Abstract

The rare decay K&#95;{L}→π^{0}νν[over ¯] was studied with the dataset taken at the J-PARC KOTO experiment in 2016, 2017, and 2018. With a single event sensitivity of (7.20±0.05&#95;{stat}±0.66&#95;{syst})×10^{-10}, three candidate events were observed in the signal region. After unveiling them, contaminations from K^{±} and scattered K&#95;{L} decays were studied, and the total number of background events was estimated to be 1.22±0.26. We conclude that the number of observed events is statistically consistent with the background expectation. For this dataset, we set an upper limit of 4.9×10^{-9} on the branching fraction of K&#95;{L}→π^{0}νν[over ¯] at the 90% confidence level.

Published
2021
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4. Search for K&#95;{L}→π^{0}νν[over ¯] and K&#95;{L}→π^{0}X^{0} Decays at the J-PARC KOTO Experiment.

Author

Ahn JK, Beckford B, Beechert J, Bryant K, Campbell M, Chen SH, Comfort J, Dona K, Hara N, Haraguchi H, Hsiung YB, Hutcheson M, Inagaki T, Kamiji I, Kawasaki N, Kim EJ, Kim JL, Kim YJ, Ko JW, Komatsubara TK, Kotera K, Kurilin AS, Lee JW, Lim GY, Lin C, Lin Q, Luo Y, Ma J, Maeda Y, Mari T, Masuda T, Matsumura T, Mcfarland D, McNeal N, Micallef J, Miyazaki K, Murayama R, Naito D, Nakagiri K, Nanjo H, Nishimiya H, Nomura T, Ohsugi M, Okuno H, Sasaki M, Sasao N, Sato K, Sato T, Sato Y, Schamis H, Seki S, Shimizu N, Shimogawa T, Shinkawa T, Shinohara S, Shiomi K, Su S, Sugiyama Y, Suzuki S, Tajima Y, Taylor M, Tecchio M, Togawa M, Tung YC, Wah YW, Watanabe H, Woo JK, Yamanaka T, and Yoshida HY

Abstract

A search for the rare decay K&#95;{L}→π^{0}νν[over ¯] was performed. With the data collected in 2015, corresponding to 2.2×10^{19} protons on target, a single event sensitivity of (1.30±0.01&#95;{stat}±0.14&#95;{syst})×10^{-9} was achieved and no candidate events were observed. We set an upper limit of 3.0×10^{-9} for the branching fraction of K&#95;{L}→π^{0}νν[over ¯] at the 90% confidence level (C.L.), which improved the previous limit by almost an order of magnitude. An upper limit for K&#95;{L}→π^{0}X^{0} was also set as 2.4×10^{-9} at the 90% C.L., where X^{0} is an invisible boson with a mass of 135  MeV/c^{2}.

Published
2019
Full Text
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